An enormous quantity of lubricating oil is consumed annually due to the necessity of changing oil at least once a year for ordinary passenger vehicles and even more frequently for fleet vehicles and vehicles subject to heavy use. This is particularly the case with vehicles and other devices using diesel engines. Manufacturers of diesel engines specify oil changes every three to four thousand miles. It is estimated that approximately four billion quarts of oil are consumed annually in the United States alone due to oil changes. In addition, the quality of oil in an engine rapidly decreases due to particulate matter, water, gasoline and acid which rapidly builds up in the lubricant and is circulated in the engine for long periods of time before recommended oil changes are made. Consequently, internal combustion engines tend to wear out long before they would wear out if only run with high quality oil.
These problems have long been recognized in the art and the patent literature includes numerous patents covering various filter-refiners. For one reason or another, none of these filter-refiners have achieved wide commercial acceptance even though one of the inventors, Adolph Fram, in the instant patent application enjoyed years of success utilizing oil filter-refiners with his taxicab fleet.
One of the difficulties frustrating acceptance of oil filter-refiners has been expense. This is primarily due to the mistaken assumption that the refiners need a heater. Heaters necessitate expensive cast components which add considerable cost to the units. As has been pointed out in the prior art, it is desirable to produce oil films in an evaporation chamber in order to facilitate removal of volatile contaminates such as gasoline, water and acid, however, the prior art has failed to provide sufficient structure to create a large oil film area.
Although the prior art does suggest in at least one patent that the air vent of a filter-refiner can be connected to the intake of the internal combustion engine with which the filter is used, there is no realization that by making this connection in an appropriate manner, the efficiency of an evaporation chamber can be increased dramatically without resorting to the application of supplemental heat. The oil is hot enough in and of itself for the refinement process and is frequently more effective for lubrication purposes when cooled. By utilizing the evaporation chamber approach, evaporation of gasoline, acid and water from the oil tends to cool the oil so that the oil returned to the engine is both purified and cool.